This invention relates generally to electrical connectors and, more particularly, to connectors for end terminating and/or daisy chaining flat or ribbon cable.
Flat cable is in common use in high density applications such as data transmission in which large quantities of data are electronically transmitted between various types of equipment. A flat cable generally comprises a plurality of spaced, parallel conductors embedded in insulation material. A conventional flat cable in widespread use, for example, has twenty-five parallel conductors spaced from each other on 0.050 inch centers embedded in a web of insulation having an overall width of about one and one-half inches. Such cable can be connected to equipment by terminating in a "dead end" connection where one end of the flat cable is joined to a connector, or by a "daisy chain" connection where a connector is joined to the flat cable between its ends. Connectors for flat cables are disclosed in U.S. Pat. Nos. 4,020,540, 4,228,709, 4,241,790, 4,393,580, and 4,687,263.
As technology progresses, the need for transmitting data faster and in greater quantities becomes more acute. In this regard, it generally would be desirable to increase the number of conductors carrying the data and it has been suggested in one case to use flat cable having as many as fifty or more conductors. Of course, if conventional inter-conductor spacing, e.g., 0.050 inches, is maintained, the width of the flat cable must increase. Conversely, if conventional cable widths are desired, it becomes necessary to space the parallel conductors closer to each other, e.g., on, 0.025 inch centers. Each approach, however, has drawbacks. In particular, the space available for cable connectors is frequently limited thereby imposing limitations on the width of the cable. On the other hand, electrical properties, such as characteristic impedance and cable cross-talk, of flat cables having conductors spaced at a fine pitch, are not compatible with many items of equipment for which their use is intended.
High density connectors for flat ribbon cables should also meet certain other design objectives. For example, a high density connector should be of a design which permits the cable terminating procedure to be fast and simple. It should be capable of both daisy chain as well as single ended connections. It should be able to mate with a connector whose height and width present a minimum profile. Further, the connector should be relatively simple in construction and economical in manufacture.